Conventionally, gate contacts are formed as both rectangles and squares, depending on their locations in an SRAM bitcell. Specifically, rectangular shaped gate contacts are formed on gate electrodes to connect the gate electrodes to trench silicides (TS), on the active or source/drain regions, to create a cross-coupling of the gate electrodes. For example, as illustrated in FIGS. 1A and 1B, gate contacts 101 are formed over gate electrodes 103. Within cross-couple region 105, the gate contacts 101 each connect a gate electrode 103 and a TS 107, which is formed between adjacent gate electrodes on the active areas of a substrate 109. The gate contacts in the cross-couple region 105 are rectangular, whereas gate contacts elsewhere in the bitcell are square. Also shown in FIGS. 1A and 1B are square source/drain contacts 111 formed over TS 107 and connected to a metal 1 (M1) layer 113 through vias 115. Some of the vias are formed directly over the source/drain contacts 111 (such as at 117), whereas others merely overlap. Further, some of the gate electrodes 103 are formed over a shallow trench isolation (STI) region 119 in substrate 109.
Multiple shapes for the gate contacts causes printability issues, particularly with more advanced technology nodes and further scaling down of semiconductor devices. In addition, as shown in FIG. 1B, the limited spacing 119 between the rectangular gate contact 101 and the adjacent gate electrode 103 in the cross-couple region 105 can reduce yield as design rules are violated, especially as the contacted poly pitch (CPP) 121 continues to shrink.
A need therefore exists for methodology enabling formation of uniform regular shaped gate contacts and the resulting device.